Is the gender gap an issue in medical trials?

15th August 2018

It is well accepted that children are not just miniature adults and so ideally should only receive drugs that have been tested in paediatric trials. However, there is also evidence that the difference between male and female patients can be just as important.

Sleeping pill, Ambien, is a good example of a drug that works differently in men and women. The US Food and Drug Administration (FDA) discovered that men metabolize the drug much faster than women. This led to the FDA cutting recommended doses for women by half.

Even the humble aspirin has very different effects on men and women in terms of lowering risk of heart disease.

Findings like these prompted the FDA to release a set of guidelines to the pharmaceutical industry detailing the exceptions for excluding a gender from clinical trials, such as testing a prostate cancer medication or other male or female-specific drug. In theory, women have been included equally in drug studies since 2001.

However, a report in the journal, Cell Metabolism, suggests that there is still a long way to go to eliminate the gender gap in medical trials. According to the report, there is still a tendency to treat the sexes as equivalent, ignoring how fluctuations of sex hormones in experimental settings impact outcomes.

The authors of this article are not alone – an article published in the journal, Cancer, also points to a gender bias in oncology trials – excluding those cancers that only present in a single sex of patient of course.

I have written before about the massive under-representation of ethnic minorities in drug trials and the actions to address this in the US. However, the difference between male and female patients is less widely reported.

Is this, as some article have suggested, because things like periods and menopause make female trial participants a more unpredictable proposition? I certainly hope not.

I suspect is it largely the fact that white, middle-aged men are the easiest (and therefore cheapest) group to recruit. Recruitment is one of the most time-consuming and expensive parts of a drug trial – failure to recruit means the whole trial will collapse.

Trials have a responsibility to investigate a drug’s effect on a sample that is as close to the target market as is practically possible. It means ensuring trials are design to account for the difference between male and female patients.

Doing so will inevitable increase the cost of some trials but if the results are more representative of a drug’s behaviour in the population isn’t it a cost that is worth bearing?

Ashley Smith

Ashley devotes most of his time to Whitehall Training. As one of the longest standing members of the team he has overseen the development of our Health and Social Care department. In his free time Ashley likes to listen to music, especially his favourite group: Orbital.